This application claims priority of Taiwanese Application No. 092208421, filed on May 8, 2003.
1. Field of the Invention
The invention relates to a heat pipe, more particularly to a heat pipe that can transfer heat quickly.
2. Description of the Related Art
FIGS. 1 to 4 illustrate a method for producing a conventional heat pipe 1 that is suitable for dissipating heat from electronic components. The method includes the steps of providing a metallic tubular body 11 with an open end portion 111 and a peripheral wall 112 defining an inner chamber 113, introducing a suitable amount of heat transfer liquid 13 into the tubular body 11 using a filling device 12, evacuating the inner chamber 113 of the tubular body 11, pinching the open end portion 111 of the tubular body 11 by means of a machine tool 5 (see FIG. 2) so as to close the open end portion 111 and so as to form a flattened sealing portion 114 (see FIG. 2), cutting a top end section 1141 of the flattened sealing portion 114 by means of a cutting machine 3 (see FIG. 3), and sealing the heat pipe 1 by a spot welding process. A welding spot, represented by numeral 14, is shown in FIG. 4.
However, in actual use, the aforementioned flattened sealing portion 114 of the heat pipe 1 is easily broken due to an external force, thereby resulting in leakage of the heat pipe 1. Furthermore, the flattened sealing portion 114 increases the length of the heat pipe 1 such that the latter has a relatively large volume. Moreover, since the liquid 13 is first introduced into the tubular body 11 followed by the evacuation process, it is possible that some of the liquid 13 will be drawn out such that the quantity of the liquid 13 in the tubular body 11 and the quality of the heat pipe 1 cannot be accurately controlled. Additionally, the method for producing the conventional heat pipe 1 is somewhat complicated.
Most importantly, heat dissipation of the conventional heat pipe 1 involves stimulating the liquid 13 in the tubular body 11 through the rising temperature of the heat source 2, such as an integrated circuit, so that the liquid 13 gradually absorbs the heat and vaporizes, as shown by upward arrows in FIG. 4. The vaporized liquid exchanges heat with the external air through convection and then condenses into liquid, thereby achieving absorption and dissipation of heat from the heat source 2. However, although a liquid can absorb heat more rapidly than a solid, since the flat bottom of the heat pipe 1, which has a slow heat absorption rate, overlies the heat source 2 for heat exchange with the heat source 2 and for heat transfer to the liquid 13, the time required to stimulate the liquid 13 in the tubular body 11 is prolonged so that heat cannot be transferred quickly.
Therefore, the object of the present invention is to provide a heat pipe that is capable of overcoming the aforementioned drawbacks of the prior art.
According to this invention, a heat pipe comprises a tubular body, a heat transfer fluid, and a heat sink member. The tubular body has opposite bottom and top ends, a peripheral wall between the bottom and top ends, and an inner chamber defined by the bottom and top ends and the peripheral wall. The heat transfer fluid is disposed in the inner chamber. The heat sink member closes the bottom end, and has a bottom face adapted to contact a heat source. The heat sink member further has a top face directed toward the inner chamber. The top face is indented downwardly to define a fluid accumulating portion. The heat transfer fluid in the fluid accumulating portion absorbs heat from the heat source and vaporizes to carry heat away from the heat source.